Canon Kabushiki Kaisha

Michiharu Aratani

Takeshi Akiyama

Tsunefumi Tanaka

Norihiro Nanba

Sadahiko Tsuji

Hiroaki Hoshi

Hiroshi Saruwatari

Kenichi Kimura

Keisuke Araki

Hiroshi Nakanishi

An optical element includes an incidence surface, one or more reflecting surfaces reflecting light from the incident surface, an emergence surface, and off-axial curved surfaces causing the light to emerge from the emergence surface. At least one of the incidence surface, the emergence surface and the one or more reflecting surfaces is a surface having diffracting action. The surface having the diffracting action is a curved surface.

Optical element and optical system having the same

An optical element has a first optical member which is a transparent body having two refracting surfaces and a reflecting, curved surface symmetric only with respect to one symmetry plane and a reference axis of which is present in the symmetry plane; and a second optical member which is a transparent body having two refracting surfaces and a reflecting surface and a reference axis of which is not present in the symmetry plane. One refracting surface of the second optical member is coupled to one refracting surface of the first optical member. The reference axis is defined by a ray passing an image center and a pupil center of an optical system including the optical element.

Optical element and optical apparatus having it

An optical system includes an optical element having a plurality of reflective surfaces integrally formed, at least one reflective surface out of the plurality of reflective surfaces of the optical element being a curved surface a normal to which at an intersecting point with a reference axis does not coincide with the reference axis, an image pickup element to which light successively reflected by the plurality of reflective surfaces is incident, and an optical member for making at least part of the light that ought to enter the image pickup element, travel in an optical path different from an optical path toward the image pickup element. The light made to travel in the different optical path by the optical member is utilized for a purpose other than image pickup by said image pickup element.

Optical system and image pickup apparatus having the same

An image pickup optical system has an optical element of a transparent, optical material including an entrance surface, at least one reflective surface, and an exit surface. The optical element has an optical power, the image pickup optical system has an image pickup element including a plurality of pixels. On the image pickup element an image is formed by light from an object through the optical element. The optical material is a material having an index change amount &Dgr;n from an absolute dry condition at the temperature of 50&deg; C. to saturation under a circumstance of the temperature being 50&deg; C. and the humidity being 90%, the index change amount &Dgr;n satisfying the following condition: &Dgr;n&lE;F&dgr;r,/(2f,L) where F is the F-number of the image pickup optical system, f is the focal length of the image pickup optical system, &dgr; is the pitch of the pixels of the image pickup element, L is the optical path length of the optical element along the reference axis, and r,is half of the length of the optical element along a direction perpendicular to a plane including the reference axis.

Growing community of inventors

Kawasaki, Japan

Michiharu Aratani